Trainer Tip – Can sitting down cause weight gain?

Trainer Tip – Can Sitting Down cause weight gain?

If you got our recent Shape Your Health Newsletter, the article was about sitting down too much. We know how important this is to reaching your fitness goals, so we thought it would be a great topic this week and have you focus on doing less sitting this week (and from now on). I know with many of our clients that sitting down can have a huge effect on fitness and movement. From my experience, most people in our program that sit down the majority of the time are not flexibly or struggle with it comes to movement and mobility. As you have heard me say over and over, if you have better movement, your body naturally has to work harder (burn more calories). The article is below but I did want to share some basic things we do sitting that can be changed

Here is a few examples of thins you can do besides sitting.Instead of This: Sitting at your desk 83 Calories burned per hourDo This: Stand at your desk 115 Calories burned per hour

Instead of This: E-mailing a coworker 96Do This: Walk to her office 128

Instead of This: Playing a seated video game 32Do This: Play Wii 178

Total calories:
697 vs. 1,448*
*based on a 140-pound woman

Can sitting too much Kill you?

We all know that physical activity is important for good health—regardless of your age, gender or body weight, living an active lifestyle can improve your quality of life and dramatically reduce your risk of death and disease. But even if you are meeting current physical activity guidelines by exercising for one hour per day (something few Americans manage on a consistent basis), that leaves 15 to 16 hours per day when you are not being active. Does it matter how you spend those hours, which account for more than 90% of your day? For example, does it matter whether you spend those 16 hours sitting on your butt, versus standing or walking at a leisurely pace? Fortunately or unfortunately, new evidence suggests that it does matter, and in a big way.

What is sedentary behavior?

Before we go any further, it’s important that we define the term “sedentary behavior”. Sedentary behavior is typically defined as any behavior with an exceedingly low energy expenditure (defined as <1.5 metabolic equivalents). In general, this means that almost any time you are sitting (e.g. working on a computer, watching TV, driving) or lying down, you are engaging in sedentary behavior. There are a few notable exceptions when you can be sitting or lying down but still expend high energy expenditure (e.g. riding a stationary bike), but in general if you are sitting down, you are being sedentary.

The above definition may seem rather intuitive, but this is not the way that the term sedentary has been used by exercise science researchers for the past 50 years. Up until very recently, referring to someone as sedentary meant simply that they were not meeting current guidelines for physical activity. In simple terms, if you were exercising for 60+ minutes/day, you were considered physically active. If you were exercising 10 minutes/day, you were sedentary. Case closed. But as we will discuss below, sedentary time is closely associated with health risk regardless of how much physical activity you perform on a daily basis. Further, it is entirely possible to meet current physical activity guidelines while still being incredibly sedentary. Thus, to quote researcher Marc Hamilton, sitting too much is not the same as exercising too little. (if you take only one thing from this post, let it be that quote from Dr Hamilton). Which is why it is so important that when we use the term “sedentary”, we are all on the same page about what that means.

In 2009 Dr Peter Katzmarzyk and colleagues at the Pennington Biomedical Research Center published an influential longitudinal paper examining the links between time spent sitting and mortality in a sample of more than 17,000 Canadians. Not surprisingly, they report that time spent sitting was associated with increased risk of all-cause and cardiovascular disease mortality (there was no association between sitting and deaths due to cancer). But what is fascinating is that the relationship between sitting time and mortality was independent of physical activity levels. In fact, individuals who sat the most were roughly 50% more likely to die during the follow-up period than individuals who sat the least, even after controlling for age, smoking, and physical activity levels. Further analyses suggested that the relationship between sitting time and mortality was also independent of body weight. This suggests that all things being equal (body weight, physical activity levels, smoking, alcohol intake, age, and sex) the person who sits more is at a higher risk of death than the person who sits less.

The greater the number of breaks taken from sedentary behavior, the lower the waist circumference, body mass index, as well as blood lipids and glucose tolerance. This was true even if the total amount of sedentary time and physical activity time were equal between individuals—the one who took breaks more frequently during their time at the office or while watching television was less obese and had better metabolic health. Importantly, the breaks taken by the individuals in this study were of a brief duration (<5 min) and a low intensity (such as walking to the washroom, or simply standing).

Quite obviously (and by definition), when you are sedentary, you are not being physically active. So while it makes intuitive sense that being sedentary reduces energy expenditure, it is likely through the reduction of very light intensity physical activity (e.g. standing, walking at a slow pace), rather than by reducing the volume of what we typically think of as exercise. This may also help explain why the relationship between sedentary behavior and health risk are often independent of moderate or vigorous physical activity.

Similarly, it has also been reported that each hour of daily television watching is associated with 167 calories, mainly through increased consumption of high calorie, low nutrient foods (e.g. the foods most commonly advertised on television). Much of this is likely just a learned behavior. Just as importantly, people may just really enjoy munching on food while relaxing on the couch. Either way, excess sitting (and TV watching in particular) seems to put us in situations where we choose to eat more than we would otherwise.

There is a rapidly accumulating body of evidence which suggests that prolonged sitting is very bad for our health, even for lean and otherwise physically active individuals. The good news? Research suggests that simply walking at a leisurely pace may be enough to rapidly undo the metabolic damage associated with prolonged sitting, a finding which is supported by epidemiological work in humans. So, while there are a lot of questions that remain unanswered (e.g. Is there a “safe” amount of daily sedentary time?), the evidence seems clear that we should strive to limit the amount of time we spend sitting. And when we do have to sit for extended periods of time (which, let’s face it, is pretty much every single day for many of us) we should take short breaks whenever possible.

Travis Saunders is a Certified Exercise Physiologist and PhD Candidate at the University of Ottawa in Ontario, Canada.